Controlled volume pump



p 22, 1954 w. A. WILLIAMS 3,149,469

CQNTROLLED VOLUME PUMP Filed April 27, 1962 2 Sheets-Sheet 1 WILLIAM A. WILLIAMS ATTORNEY Sept. 22, 1964 w. A. WILLIAMS 3,149,469

CONTROLLED VOLUME PUMP Filed April 27, 1962 2 Sheets-Sheet 2 INVENTOR.

WILLIAM A. WILLIAMS wgigdj ATTORNEY I United States Patent Office 3,149,4h9 Patented Sept. 22, 1964 3,149,459 CONTROLLED VGLUME PUMP Wiliiam A. Wiiiiams, Philadelphia, Pa, assignor to Milton Roy Company, Philadelphia, Pa., a corporation of Pennsylvania Filed Apr. 27, 1962, Ser. No. 199,613 8 Ciaims. (Cl. 6t)54.6)

This invention relates to improvements in pumping means and more particularly to pumps such as controlled volume pumps for accurately and repeatedly pumping predetermined quantities of liquid, such pumps having particular utility in industrial processes involved in paper making, water treatment, and petroleum refining, for example.

It is an object of this invention to provide a particularly accurate and improved pump of the type including a pumping chamber separated from a hydraulic pressure chamber by a movable wall which is preferably in the form of a flexible diaphragm and is movable to and from a limit position so as to pump fluid into and out of the pumping chamber, the wall being moved by hydraulic fluid forced into and withdrawn from the hydraulic pressure chamber by piston or plunger means reciprocable in a cylinder through pressure and return strokes, the improved pump comprising means for making the eflective length of the return strokes to exceed the eifective length of the pressure strokes so that the movable wall is positively returned to its limit position upon each return stroke regardless of slight leakage past the plunger on the pressure and/ or return strokes.

Another object of this invention is the provision of an improved pump of the foregoing character wherein the means for making the effective length of the plunger return stroke to be in excess of the length of the pressure stroke comprises an hydraulic fluid reservoir, valve means in a passage between the reservoir and the hydraulic pressure chamber for controlling fluid flow in either direction therebetween so that when the valve means is closed movement of the plunger will cause hydraulic fluid to work the diaphragm, but when the valve means is open movement of the plunger results in hydraulic fluid flow into and out of the reservoir rather than in working of the diaphragm, and drive means for operating the plunger and valve means in timed relation so that the valve means is closed for a longer portion of the return stroke than of the pressure stroke.

As another object this invention aims to provide a pump as described in the foregoing paragraphs, the valve means of which may be adjusted to select the volume of pumpage to be effected upon each pumping cycle without varying the differential between the effective lengths of the pressure and withdrawal strokes of the plunger, the valve means preferably comprising a slide valve member movable in timed relation with the plunger and cooperating with a ported sleeve member which is adjustably positionable to select the positions of plunger travel at which the valve means will open and close communication between the hydraulic pressure chamber and the reservoir, and hence to select the amount of pumpage which will be effected. Preferably, the valve member is driven in timed relation to the plunger by lost motion connecting means to provide the differential in effective stroke lengths of the piston.

Other objects and advantages of the invention will become apparent from the following detailed description of a preferred form of controlled volume pump embodying the invention, the description being read in conjunction with the accompanying sheet of drawings forming a part of this specification and in which- FIG. 1 is a longitudinal vertical sectional view of a F controlled volume pump embodying the invention;

FIG. 2 is a transverse sectional view of the pump of FIG. 1 taken substantially along line 2-2 of FIG. 1; and

FIG. 3 is an enlarged fragmentary view of a portion of FIG. 2.

In the form of the invention shown in the drawings there is provided a controlled volume pump 10 comprising a pump body 11 including a diaphragm pump portion 11a, a cylinder portion 1117, a drive housing portion 110, and a valve portion 11d. Diaphragm pump portion 11a of body 11 is generally circular in configuration as viewed in FIG. 1 and has a hydraulic fluid pressure chamber 12 therein, best shown in FIG. 2 and defined in part by a movable wall in the form of a flexible diaphragm 13. Diaphragm 13 is formed of a material compatible with the fluid to be pumped, for example: stainless steel or Teflon polytetrafluoroethylene plastic for use with corrosive fluids, and has its periphery clamped between body portion 11a and a removable pump member 14 secured to body portion 11a by a series of screws 15'. Body portion 11a includes a wall 13 disposed within chamber 12 and having drilled openings 18a therethrough. Wall 18 presents a concave surface to diaphragm 13 and serves to limit movement or displacement of the diaphragm in the direction of hydraulic pressure chamber 12.

Pump member 14 has a pumping chamber 29 therein, defined in part by diaphragm 13 and served by inlet and outlet ports 21 and 22 respectively, which ports are provided with suitable check valve means 23 and 24. Pump member 14 also includes a wall 26 disposed within chamber Zii, which wall presents a concave surface to diaphragm 13 and is provided with drilled openings 2511. Wall 26 serves as a limit to displacement of diaphragm 13 in the direction of pumping chamber 20.

When check valve means 23 and 24 are connected by suitable piping into a system containing a liquid, diaphragm 13 may be worked back and forth in the space between walls 18 and 26 to alternately draw liquid into pumping chamber 20 through port 21 and to displace liquid from the pumping chamber through outlet port 22. Pressure chamber 12 is filled with hydraulic fluid and the working of diaphragm 13 is eflected by forcing additional hydraulic fluid into chamber 12 where it acts to move diaphragm 13 to displace liquid from chamber 20, and by withdrawing hydraulic fluid from chamber 12, so as to displace diaphragm 13 to the left and draw fluid into chamber 2 The movement of hydraulic fluid into and out of hydraulic pressure chamber 12 is eifected by reciprocation of a plunger 30 in a cylinder 31 defined in cylinder portion 11]) of pump body 11. Cylinder 31, which is conveniently closed at one end by a plug 32, is placed into communication with chamber 12 via a drilled passage 33 which opens in cylinder 31 adjacent the plug 32.

Plunger 30 is reciprocated through pressure and return strokes by drive means generally housed within body portion and including a shaft 34 of an electric motor 35 mounted on body 11. A worm shaft 36 is spiined at one end 36a to shaft 34 and has its other end 36b suitably journaled in a bearing means 37 in body 11. A worm 38 is secured to shaft 36 for rotation therewith and is in meshing engagement with a worm gear 49 which rotates on a transverse shaft 41 supported in body 11. Worm gear 419 has an integrately formed eccentric 42 on which the large end 43a of a connecting rod 43 is journaled. Connecting rod 43 has its small end 43b connected by a wrist pin 44 to an enlarged clevis end 30a of plunger 36 extending into drive housing body portion 110. Operation of motor 35 rotates shaft 36 and worm 38 so as to drive worm gear 40 and eccentric 42 at a considerably reduced rate of rotation. The rotary motion of worm gear 443 and eccentric 42 therewith is converted by connecting rod 43 3 into reciprocating motion of plunger 38 as will be understood by those skilled in the art to which the invention pertains.

Body portion 110 serves as a reservoir 45 for a body of hydraulic fluid the upper lever of which is indicated at 46. A horizontal passage 47 is formed in body 11 and leads from the reservoir to a vertical passage 48 which serves in part as a filler opening, normally substantially closed by a vented plug 49. A bore 50 extends through valve portion 11d of body 11 from the reservoir 45 to the exterior of a projecting, cylindrical boss 52 of the body portion 11d, the bore 58 intersecting with the vertical passage 48. An adjustable, ported sleeve member 54 having a solid end 54a is reciprocably disposed in bore 50 with the solid end 54a projecting from boss 52. The other end 54b of sleeve member 54 has a central bore 55 which is placed in communication with vertical passage 48 by ports 56 in the member 54. An adjusting collar 58 is secured on a stepped portion of end 54a of sleeve member 54 by a snap ring 59. Collar 58 has internal threads engaging an externally threaded portion 60 of boss 52.

Rotation of collar 58 on threaded boss 52 is adapted to longitudinally adjust the position of ported sleeve member 54 within bore 58 to selectively regulate the volume of pumpage of pump device 10 in a manner which will become apparent as the description proceeds.

Sleeve member 54 has a port 62 leading from bore 55 to an axial groove 63 formed in the sleeve member. Groove 63 overlies one end of a passage 64 which is formed in pump body 11 and opens at its other end in hydraulic fluid pressure chamber 12. Sleeve member 54 is conveniently provided with rings 66 at opposite ends of groove 63 and beyond passage 48 to provide a positive seal between the sleeve member and bore 58.

A cylindrical slide valve member 68 is reciprocably disposed in bore 55 of the sleeve member 54 and serves to control flow of hydraulic fluid through port 62 and hence controls flow between reservoir 45 and hydraulic fluid pressure chamber 12. Operation of valve member 68 isreifected in timed relation to reciprocation of plunger 38 by means of a lost motion connection including an H-shaped arm 69 having its lower bifurcated end 6% secured to enlarged plunger end 30a by screws 70. Arm 67 has its upper bifurcated end 6% engaged in a groove 68a of valve member 68. Groove 68a is appreciably wider than the thickness of arm 69 so that motion is lost to the valve member upon each reversal of direction of plunger 30.

In the drawings, apparatus is illustrated with plunger 30 in its farthest point of movement in a pressure stroke, slide valve 68 is in closing relation to port 62 thereby confining hydraulic fluid between plunger 30 and diaphragm 13, and the latter is deflected to the right or toward pumping chamber 20. The operation of apparatus 10 will now be described, assuming motor 35 to be running and worm 39 and worm gear 40 to be driving eccentric 42 in a counterclockwise direction. Rotation of eccentric 42 is converted by connecting rod 43 to linear motion of plunger 38 which is moved to the left as it commences its return stroke. Return movement of plunger 30 effects withdrawal of hydraulic fluid from hydraulic pressure chamber 12 through passage 33 and into cylinder 31 and consequent movement of diaphragm 13 toward the curved surface of wall 18. This movement of diaphragm 13 reduces the pressure in pumping chamber 20, thereby causing check valve means 24 to close and check Valve means 23 to open admitting into the chamber the liquid or other fluid to be pumped by the apparatus 10.

Because groove 68a of slide valve 68 is wider than the thickness of arm 69, slide valve 68 will remain stationary until movement of plunger causes arm 69 to traverse groove 68a, after which it begins to move the slide valve to the left with the plunger. Diaphragm 13 will continue to follow movement of plunger 30 to the left until the diaphragm positively engages the curved surface of wall 18 in hydraulic pressure chamber 12. Thereafter, movement to the left of plunger 30 and of slide valve 68 will continue until the plunger and slide valve 68 reach their maximum positions of return as shown in dot and dash lines in FIG. 1, during which movement slide valve 68 is withdrawn from covering relationship to port 62. The opening of port 62 occurs after diaphragm 13 has engaged the limiting wall 18, and before plunger 30 reaches its extreme left hand position. The opening of port 62 places reservoir 45 in free communication with hydraulic pressure chamber 12 via passages 47 and 48, ports 56, bore 55, port 62, and passage 64, thereby terminating the eflective or diaphragm working portion of the return stroke of the plunger and permitting the remainder of the return stroke to draw hydraulic fluid from reservoir 45 into cylinder 31.

Continued rotation of shaft 41 causes connecting rod 43 to reverse the direction of movement of plunger 30 causing it to move from its extreme left hand position to the right as viewed in the drawings. As plunger 38 moves to the right, hydraulic fluid is forced from cylinder 31 through the aforementioned passages and ports, including now open port 62, to the reservoir 45. At the beginning of this movement, slide valve 68 remains stationary until arm 69 again traverses groove 68a and thereafter the slide valve moves to the right with plunger 30 toward port 62. When slide valve 68 closes port 62 a predetermined quantity of hydraulic fluid is thereby confined between plunger 30 and diaphragm 13, and continued movement to the right of plunger 38 will force hydraulic fluid through passage 33 into hydraulic pressure chamber 12 causing the diaphragm to be moved to the right and to displace liquid from pumping chamber 20 through check valve means 24. The movement of plunger 30 and of diaphragm 13 will continue to the right until plunger 30 has reached its extreme right hand or full line position shown in the drawings.

It will be recognized that the effective lengths of the pressure and return strokes of plunger 30 are governed by the closing and opening of port 62 by slide valve 68 and that because of the lost motion connection effected by arm 69 and groove 68a between plunger 30 and slide valve 68 the effective length of the return stroke will exceed the effective length of the pressure stroke by an amount equal to twice the difference in size between groove 68a and arm 69. This differential in effective stroke lengths assures the positive return of diaphragm 13 to its limit position against wall 18 once in every operating cycle of the apparatus 10. Also, the opening of port 62 after diaphragm 13 reaches its limit position but before plunger 30 reaches its extreme left hand position permits hydraulic fluid 45 to be drawn into cylinder 31 to replace any slight loss or leakage of hydraulic fluid around plunger 30 duringthe effective pressure strokes.

The effective lengths of the pressure and return strokes may be adjusted to vary the volume of pumpage effected from chamber 28 upon each cycle of the apparatus, without changing the differential by which the effective return stroke exceeds the effective pressure stroke, by rotating collar 58 to selectively position sleeve member 54 within bore 50. Thus, movement'of sleeve member 54 to the right of the position illustrated in FIG. 1 will cause port 62 to be closed later in the right hand movement of plunger 30 and opened earlier in the left hand movement of the plunger, thereby shortening the effective strokes and reducing the volume rate of pumpage. Conversely, movement of sleeve member 54 to the left of the position illustrated in FIG. 1 will increase the effective stroke lengths and the rate of pumpage.

Because passage 64 is located at the top of hydraulic pressure chamber 12, any gas which may come out of the hydraulic fluid in the plunger cylinder and pressure chamber will'rise and be vented through passage 64 to the vertical passage 48 for venting through plug 49. This air or gas release feature permits the pump to operate continuously for accurate controlled volume metering without becoming air bound.

From the foregoing detailed description of a presently preferred embodiment of the invention, it will be appreciatecl that there has been provided by my invention an improved pump device of the type wherein hydraulic fluid is confined between a moving plunger and a movable wall or diaphragm to eflect pumping, the invention pro viding means by which the diaphragm is returned to a predetermined limit position during each cycle of operation and the quantity of hydraulic fluid between the plunger and the diaphragm is adjusted during each cycle of the operation, thereby providing a particularly accurate and reliable pumping device useful in processes requiring close control of liquid movement. It will also be appreciated that pumping devices embodying the present invention may be accurately adjusted to vary the volume of pumpage efiected, and that this adjustment may be made even while the apparatus is running.

Although the present invention has been described in considerable detail with reference to a specific pump device embodying the invention, it is understood that the invention is not limited thereto, but rather the invention includes all those modifications, adaptations, substitutions, and use as are reasonably embraced by the scope of the claims hereof.

Having thus described my invention, I claim:

1. A device for hydraulically moving a movable element from and to a predetermined limit position against stop means, said device comprising:

(a) a body defining a cylinder communicating with a pressure chamber defined in part by said movable element,

(b) a plunger disposed in said cylinder for recipro cating movement through pressure and return strokes,

(c) an hydraulic fluid reservoir,

(d) means defining an hydraulic fluid passage between said reservoir and said pressure chamber and including a ported member movably mounted in said body,

(e) valve means cooperable with said ported member for controlling flow of hydraulic fluid in said passage,

(f) said valve means having a closed position confining hydraulic fluid between said plunger and said movable element so that the latter follows pressure and return movements of said plunger, and said valve means having an open position in which hydraulic fluid flows freely between said reservoir and said pressure chamber,

(3) drive means for operating said plunger and said valve means in timed relation so that the effective length of said return strokes exceeds the eflfective length of said pressure strokes, whereby said movable element is returned to its limit position upon each return stroke,

and

(11) control means for adjustably positioning said ported member to vary the efiective lengths of said pressure and return strokes and hence to vary the movement of said movable element.

2. A device as defined in claim 1 and wherein said ported member comprises an axially positionable sleeve, and said valve means comprises a valve member reciprocable in said sleeve.

3. A device as defined in claim 2 and wherein said control means comprises screw means between said sleeve and said body for adjustably positioning said sleeve.

4. A device as defined in claim 1 and wherein said hydraulic fluid passage communicates with the top of said pressure chamber and is vented to the atmosphere.

5. A device for hydraulically moving a movable element from and to a predetermined limit position against stop means, said device comprising:

(a) a body defining a cylinder communicating with a pressure chamber defined in part by said movable element,

(b) a plunger disposed in said cylinder for reciprocating movement through pressure and return strokes,

(c) an hydraulic fluid reservoir,

(:1) means defining an hydraulic fluid passage between said reservoir and said pressure chamber,

(e) valve means for controlling flow of hydraulic fiuid in said passage,

(1) said valve means having a closed position confining hydraulic fluid between said plunger and said movable element so that the latter follows pressure and return movements of said plunger, and said valve means having an open position in which hydraulic fluid flows freely between said reservoir and said pressure chamber,

and

(g) drive means including a lost motion connection between said plunger and said valve means for operating said plunger and said valve means in timed relation so that the efiective length of said return strokes always exceeds the eflective length of said pressure strokes, whereby said movable element is returned to its limit position upon each return stroke.

6. A device for hydraulically moving a movable element from and to a predetermined limit position against stop means, said device comprising:

(a) a body defining a cylinder communicating with a pressure chamber defined in part by said movable element,

(1)) a plunger disposed in said cylinder for reciprocating movement through pressure and return strokes,

(c) an hydraulic fluid reservoir,

(d) means defining an hydraulic fluid passage between said reservoir and said pressure chamber including a ported member movably mounted in said body,

(e) slide valve means cooperable with said ported member for controlling flow of hydraulic fluid in said passage,

(f) said slide valve means having a closed position confining hydraulic fluid between said plunger and said movable element so that the latter follows pressure and return movements of said plunger, and said slide valve means having an open position in which hydraulic fluid flows freely between said reservoir and said pressure chamber,

(g) drive means including a lost motion connection between said plunger and said slide valve means for operating said plunger and said slide valve means in timed relation so that the effective length of said return strokes exceeds the eifective length of said pressure strokes, whereby said movable element is returned to its limit position upon each return stroke,

and

(11) control means for adjustably positioning said ported member to vary the effective lengths of said pressure and return strokes and hence to vary the movement of said movable element.

7. A device as defined in claim 6 and wherein said ported member comprises an axially positionable sleeve, and said slide valve means comprises a valve member reciprocable in said sleeve.

8. A device as defined in claim 6 and wherein said control means comprises screw means between said sleeve and said body for adjustably positioning said sleeve.

References Cited in the file of this patent UNITED STATES PATENTS 2,975,599 ennett Mar. 21, 1961 FOREIGN PATENTS 633,708 Great Britain Dec. 19, 1949 

1. A DEVICE FOR HYDRAULICALLY MOVING A MOVABLE ELEMENT FROM AND TO A PREDETERMINED LIMIT POSITION AGAINST STOP MEANS, SAID DEVICE COMPRISING: (A) A BODY DEFINING A CYLINDER COMMUNICATING WITH A PRESSURE CHAMBER DEFINED IN PART BY SAID MOVABLE ELEMENT, (B) A PLUNGER DISPOSED IN SAID CYLINDER FOR RECIPROCATING MOVEMENT THROUGH PRESSURE AND RETURN STROKES, (C) AN HYDRAULIC FLUID RESERVOIR, (D) MEANS DEFINING AN HYDRAULIC FLUID PASSAGE BETWEEN SAID RESERVOIR AND SAID PRESSURE CHAMBER AND INCLUDING A PORTED MEMBER MOVABLY MOUNTED IN SAID BODY, (E) VALVE MEANS COOPERABLE WITH SAID PORTED MEMBER FOR CONTROLLING FLOW OF HYDRAULIC FLUID IN SAID PASSAGE, (F) SAID VALVE MEANS HAVING A CLOSED POSITION CONFINING HYDRAULIC FLUID BETWEEN SAID PLUNGER AND SAID MOVABLE ELEMENT SO THAT THE LATTER FOLLOWS PRESSURE AND RETURN MOVEMENTS OF SAID PLUNGER, AND SAID VALVE MEANS HAVING AN OPEN POSITION IN WHICH HYDRAULIC FLUID FLOWS FREELY BETWEEN SAID RESERVOIR AND SAID PRESSURE CHAMBER, (G) DRIVE MEANS FOR OPERATING SAID PLUNGER AND SAID VALVE MEANS IN TIMED RELATION SO THAT THE EFFECTIVE LENGTH OF SAID RETURN STROKES EXCEEDS THE EFFECTIVE LENGTH OF SAID PRESSURE STROKES, WHEREBY SAID MOVABLE ELEMENT IS RETURNED TO ITS LIMIT POSITION UPON EACH RETURN STROKE, AND (H) CONTROL MEANS FOR ADJUSTABLY POSITIONING SAID PORTED MEMBER TO VARY THE EFFECTIVE LENGTHS OF SAID PRESSURE AND RETURN STROKES AND HENCE TO VARY THE MOVEMENT OF SAID MOVABLE ELEMENT. 